CN113646356B

CN113646356B - Light-emitting element and composition for light-emitting element

Info

Publication number: CN113646356B
Application number: CN202080025153.5A
Authority: CN
Inventors: 佐佐田敏明; 松本龙二
Original assignee: Sumitomo Chemical Co Ltd
Current assignee: Sumitomo Chemical Co Ltd
Priority date: 2019-03-29
Filing date: 2020-03-16
Publication date: 2023-07-25
Anticipated expiration: 2040-03-16
Also published as: US20220173336A1; EP3950764A1; WO2020203209A1; CN113646356A; JP6934967B2; EP3950764A4; TW202102513A; KR20210148212A; JP2020167388A

Abstract

Provided are a composition useful for producing a light-emitting element having excellent light-emitting efficiency, and a light-emitting element containing the composition. A light-emitting element comprising an anode, a cathode, and an organic layer disposed between the anode and the cathode and containing a composition for a light-emitting element, wherein the composition for a light-emitting element comprises a metal complex represented by formula (2) and has a structure comprising a boron atom and an oxygen atom, a sulfur atom, a selenium atom, or an sp in the ring ³ A compound (B) having a condensed heterocyclic skeleton (B) of at least 1 of a carbon atom and a nitrogen atom.

Description

Light-emitting element and composition for light-emitting element

Technical Field

The present invention relates to a light-emitting element and a composition for a light-emitting element.

Background

Light-emitting elements such as organic electroluminescent elements can be suitably used for displays and illumination, for example. As a light-emitting material for a light-emitting layer of a light-emitting element, for example, patent document 1 proposes a composition containing a compound B0 and a metal complex G1 or a metal complex Firpic.

[ chemical formula 1]

As a light-emitting material for a light-emitting layer of a light-emitting element, for example, patent document 2 proposes a composition containing a Thermally Activated Delayed Fluorescence (TADF) compound T0 and a metal complex G3.

[ chemical formula 2]

Prior art literature

Patent literature

Patent document 1: japanese patent laid-open No. 2018-043984

Patent document 2: international publication No. 2017/154884

Disclosure of Invention

Problems to be solved by the invention

However, the light-emitting element manufactured using the above composition is not necessarily sufficient in light-emitting efficiency.

Accordingly, an object of the present invention is to provide a composition useful for producing a light-emitting element having excellent light-emitting efficiency, and to provide a light-emitting element containing the composition.

Means for solving the problems

The present inventors have made intensive studies to solve the above problems, and as a result, have found that a light-emitting element excellent in light-emitting efficiency can be formed by a combination of a specific metal complex and a specific compound (B), and have completed the present invention. The metal complex G1 of patent document 1 is a metal complex having no group represented by the following formula (1-T). The compound T0 of patent document 2 is a compound having no condensed heterocyclic skeleton (b) described below.

That is, the present invention provides the following [1] to [20].

[1] A light-emitting element comprising an anode, a cathode, and an organic layer comprising a composition for a light-emitting element, which is provided between the anode and the cathode,

The composition for a light-emitting element contains

A metal complex represented by the formula (2), and

having boron atoms contained within the ring and selected from oxygen atoms, sulfur atoms, selenium atoms, sp ³ A compound (B) having a condensed heterocyclic skeleton (B) of at least 1 of a carbon atom and a nitrogen atom.

[ chemical formula 3]

[ in the above-mentioned, a method for producing a semiconductor device,

M ² represents rhodium atoms, palladium atoms, iridium atoms or platinum atoms.

n ³ Represents an integer of 1 or more, n ⁴ And represents an integer of 0 or more. Wherein at M ² In the case of rhodium or iridium atoms, n ³ +n ⁴ 3, at M ² In the case of palladium or platinum atoms, n ³ +n ⁴ 2.

E ^L Represents a carbon atom or a nitrogen atom. E (E) ^L Where there are plural, they may be the same or different from each other.

Ring L ¹ Represents an aromatic heterocyclic ring comprising a six-membered ring, which ring may have a substituent. Where there are plural substituents, they may be the same or different and may be bonded to each other to form a ring together with the atoms to which each is bonded. Ring L ¹ Where there are plural, they may be the same or different.

Ring L ² Represents an aromatic hydrocarbon ring or an aromatic heterocyclic ring, and these rings may have a substituent. Where there are plural substituents, they may be the same or different and may be bonded to each other to form a ring together with the atoms to which each is bonded. Ring L ² Where there are plural, they may be the same or different.

Ring L ¹ May have a substituent and a ring L ² The substituents may be the same or different, and may be bonded to each other to form a ring together with the atoms to which each is bonded.

Wherein, the ring L ¹ And ring L ² Of which at least 1 has a group represented by the formula (1-T) as a substituent. The presence of a group of the formula (1-T)In the case of a plurality of them, they may be the same or different.

A ³ －G ² －A ⁴ A bidentate ligand representing an anionic nature. A is that ³ And A ⁴ Each independently represents a carbon atom, an oxygen atom, or a nitrogen atom, and these atoms may be atoms constituting a ring. G ² Represents a single bond, or is bonded with A ³ And A ⁴ Together forming a group of bidentate ligands. A is that ³ －G ² －A ⁴ Where there are plural, they may be the same or different.]

[ chemical formula 4]

-R ^1T (1-T)

[ formula, R ^1T Represents alkyl, cycloalkyl, alkoxy, cycloalkoxy, aryloxy, aryl, monovalent heterocyclic groups or substituted amino groups, which may have substituents. Where there are plural substituents, they may be the same or different and may be bonded to each other to form a ring together with the atoms to which each is bonded.]

[2] The light-emitting element according to [1], wherein,

The above-mentioned ring L ¹ Is a pyridine ring, a diazabenzene ring, an azanaphthalene ring or a naphthyridine ring, and these rings may have a substituent.

[3] The light-emitting element according to [2], wherein,

the above-mentioned ring L ¹ Is a pyridine ring, a diazabenzene ring, a quinoline ring or a naphthyridine ring, which may have a substituent, and

r is as described above ^1T Is alkyl, cycloalkyl, aryl, monovalent heterocyclic group or substituted amino, which groups may have substituents.

[4] The light-emitting element according to [2], wherein,

the above-mentioned ring L ¹ Is an isoquinoline ring which may have a substituent, and

r is as described above ^1T Is aryl, monovalent heterocyclic group or substituted amino, and these groups may have a substituent.

[5] The light-emitting element according to any one of [1] to [4], wherein,

the above-mentioned ring L ² Is a benzene ring, a pyridine ring or a diazabenzene ring, and these rings may have substituents.

[6] The light-emitting element according to any one of [1] to [5], wherein,

r is as described above ^1T Is an aryl group which may have a substituent or a monovalent heterocyclic group which may have a substituent.

[7] The light-emitting element according to any one of [1] to [6], wherein,

the condensed heterocyclic skeleton (b) described above contains a boron atom and at least 1 selected from the group consisting of an oxygen atom, a sulfur atom and a nitrogen atom in the ring.

[8] The light-emitting element according to [7], wherein,

the condensed heterocyclic skeleton (b) contains a boron atom and a nitrogen atom in the ring.

[9] The light-emitting element according to any one of [1] to [6], wherein,

the compound (B) is a compound represented by the formula (1-1), a compound represented by the formula (1-2), or a compound represented by the formula (1-3).

[ chemical formula 5]

[ in the above-mentioned, a method for producing a semiconductor device,

Ar ¹ 、Ar ² and Ar is a group ³ Each independently represents an aromatic hydrocarbon group or a heterocyclic group, and these groups may have a substituent. Where there are plural substituents, they may be the same or different and may be bonded to each other to form a ring together with the atoms to which each is bonded.

Y ¹ Represents an oxygen atom, a sulfur atom, a selenium atom, -N (Ry) -represented group, an alkylene group or a cycloalkylene group, and these groups may have a substituent. Where there are plural substituents, they may be the same or different and may be bonded to each other to form a ring together with the atoms to which each is bonded.

Y ² And Y ³ Each independently represents a single bond, an oxygen atom,Sulfur atom, selenium atom, -N (Ry) -indicated group, alkylene or cycloalkylene group, these groups may have a substituent. Where there are plural substituents, they may be the same or different and may be bonded to each other to form a ring together with the atoms to which each is bonded. Ry represents a hydrogen atom, an alkyl group, a cycloalkyl group, an aryl group or a monovalent heterocyclic group, and these groups may have a substituent. Where there are plural substituents, they may be the same or different and may be bonded to each other to form a ring together with the atoms to which each is bonded. When there are a plurality of Ry, they may be the same or different. Ry may be bonded to Ar directly or via a linking group ¹ 、Ar ² Or Ar ³ And (5) bonding.]

[10] The light-emitting element according to [9], wherein,

above Y ¹ Y is as described above ² And Y is as described above ³ Is an oxygen atom, a sulfur atom or a group represented by-N (Ry) -.

[11] The light-emitting element according to [10], wherein,

above Y ¹ Y is as described above ² And Y is as described above ³ is-N (Ry) -the group shown.

[12] The light-emitting element according to any one of [1] to [11], wherein,

the absolute value of the difference between the energy level of the lowest triplet excited state of the compound (B) and the energy level of the lowest singlet excited state of the compound (B) is 0.50eV or less.

[13] The light-emitting element according to any one of [1] to [12], wherein,

the composition for a light-emitting element further comprises a compound represented by the formula (H-1).

[ chemical formula 6]

[ in the above-mentioned, a method for producing a semiconductor device,

Ar ^H1 and Ar is a group ^H2 Each independently represents an aryl group, a monovalent heterocyclic group or a substituted amino group, which may haveA substituent. Where there are plural substituents, they may be the same or different and may be bonded to each other to form a ring together with the atoms to which each is bonded.

n ^H1 And represents an integer of 0 or more.

L ^H1 Represents arylene, divalent heterocyclic, alkylene or cycloalkylene groups, which may have substituents. Where there are plural substituents, they may be the same or different and may be bonded to each other to form a ring together with the atoms to which each is bonded. L (L) ^H1 Where there are plural, they may be the same or different.]

[14] The light-emitting element according to any one of [1] to [13], wherein,

the composition for a light-emitting element further contains at least 1 selected from the group consisting of a hole-transporting material, a hole-injecting material, an electron-transporting material, an electron-injecting material, a light-emitting material, an antioxidant, and a solvent.

[15] A composition for a light-emitting element, comprising

A metal complex represented by the formula (2), and

[ chemical formula 7]

[ in the above-mentioned, a method for producing a semiconductor device,

E ^L Representing carbon atoms or nitrogen atomsAnd (5) a seed. E (E) ^L Where there are plural, they may be the same or different from each other.

Wherein, the ring L ¹ And ring L ² Of which at least 1 has a group represented by the formula (1-T) as a substituent. In the case where there are plural groups represented by the formula (1-T), they may be the same or different.

[ chemical formula 8]

-R ^1T (1-T)

[ formula, R ^1T Represents alkyl, cycloalkyl, alkoxy, cycloalkoxy, aryloxy, aryl, monovalent heterocyclic groups or substituted amino groups, which may have substituents. The substituent is at Where there are plural, they may be the same or different and may be bonded to each other to form a ring together with the atoms to which each is bonded.]

[16] The composition for a light-emitting element according to [15], wherein,

[17] The composition for a light-emitting element according to [15], wherein,

the above-mentioned ring L ¹ Is an isoquinoline ring which may have a substituent, and R as described above ^1T Is aryl, monovalent heterocyclic group or substituted amino, and these groups may have a substituent.

[18] The composition for a light-emitting element according to any one of [15] to [17], wherein,

[19] The composition for a light-emitting element according to any one of [15] to [18], wherein,

also contains a compound shown as a formula (H-1).

[ chemical formula 9]

[ in the above-mentioned, a method for producing a semiconductor device,

Ar ^H1 and Ar is a group ^H2 Each independently represents an aryl group, a monovalent heterocyclic group, or a substituted amino group, and these groups may have a substituent. Where there are plural substituents, they may be the same or different and may be bonded to each other to form a ring together with the atoms to which each is bonded.

n ^H1 And represents an integer of 0 or more.

L ^H1 Represents arylene, divalent heterocyclic, alkylene or cycloalkylene radicals, which may haveHas substituents. Where there are plural substituents, they may be the same or different and may be bonded to each other to form a ring together with the atoms to which each is bonded. L (L) ^H1 Where there are plural, they may be the same or different.]

[20] The composition for a light-emitting element according to any one of [15] to [19], wherein,

and at least 1 selected from the group consisting of a hole transporting material, a hole injecting material, an electron transporting material, an electron injecting material, a light emitting material, an antioxidant, and a solvent.

ADVANTAGEOUS EFFECTS OF INVENTION

According to the present invention, a composition useful for producing a light-emitting element excellent in light-emitting efficiency can be provided. Further, according to the present invention, a light-emitting element containing the composition can be provided.

Detailed Description

Hereinafter, preferred embodiments of the present invention will be described in detail.

Description of common terminology

The terms commonly used in the present specification are as follows unless otherwise specified.

"room temperature" means 25 ℃.

Me represents methyl, et represents ethyl, bu represents butyl, i-Pr represents isopropyl, and t-Bu represents tert-butyl.

The hydrogen atom may be deuterium atom or protium atom.

"Low molecular weight compound" means a compound having no molecular weight distribution and a molecular weight of 1X 10 ⁴ The following compounds.

The term "polymer compound" means a polymer having a molecular weight distribution and a number average molecular weight of 1X 10 in terms of polystyrene ³ Above (e.g. 1X 10) ³ ～1×10 ⁸ ) Is a polymer of (a).

"structural unit" means that 1 or more units are present in the polymer compound.

The polymer compound may be any of a block copolymer, a random copolymer, an alternating copolymer, and a graft copolymer, or may be in other forms.

When the polymer compound has a terminal group, the polymer compound is preferably a stable group because the polymer compound has a residual polymerization active group, and therefore, when the polymer compound is used for the production of a light-emitting element, there is a possibility that the light-emitting property or the luminance lifetime may be lowered. The terminal group of the polymer compound is preferably a group conjugated to the main chain, and examples thereof include an aryl group or a monovalent heterocyclic group bonded to the main chain of the polymer compound via a carbon-carbon bond.

"alkyl" may be any of straight and branched. The number of carbon atoms of the straight-chain alkyl group is usually 1 to 50, preferably 1 to 20, more preferably 1 to 10, excluding the number of carbon atoms of the substituent. The number of carbon atoms of the branched alkyl group is usually 3 to 50, preferably 3 to 20, more preferably 4 to 10, excluding the number of carbon atoms of the substituent.

The alkyl group may have a substituent. Examples of the alkyl group include methyl, ethyl, propyl, isopropyl, butyl, 2-butyl, isobutyl, tert-butyl, pentyl, isopentyl, 2-ethylbutyl, hexyl, heptyl, octyl, 2-ethylhexyl, 3-propylheptyl, decyl, 3, 7-dimethyloctyl, 2-ethyloctyl, 2-hexyldecyl and dodecyl. The alkyl group may be a group in which part or all of hydrogen atoms in these groups are substituted with cycloalkyl groups, alkoxy groups, cycloalkoxy groups, aryl groups, fluorine atoms, or the like. Examples of such an alkyl group include trifluoromethyl, pentafluoroethyl, perfluorobutyl, perfluorohexyl, perfluorooctyl, 3-phenylpropyl, 3- (4-methylphenyl) propyl, 3- (3, 5-di-hexylphenyl) propyl and 6-ethoxyhexyl.

The number of carbon atoms of the "cycloalkyl" group is usually 3 to 50, preferably 4 to 10, excluding the number of carbon atoms of the substituent. Cycloalkyl groups may have substituents. Examples of cycloalkyl groups include cyclohexyl and methylcyclohexyl.

The number of carbon atoms of the "alkylene" is usually 1 to 20, preferably 1 to 15, more preferably 1 to 10, excluding the number of carbon atoms of the substituent. The alkylene group may have a substituent. Examples of the alkylene group include methylene, ethylene, propylene, butylene, hexylene and octylene.

The number of carbon atoms of the "cycloalkylene group" is usually 3 to 20, preferably 4 to 10, excluding the number of carbon atoms of the substituent. The cycloalkylene group may have a substituent. Examples of the cycloalkylene group include cyclohexylene group.

The "aromatic hydrocarbon group" refers to a group in which 1 or more hydrogen atoms directly bonded to atoms constituting a ring are removed from an aromatic hydrocarbon. A group obtained by removing 1 hydrogen atom directly bonded to an atom constituting a ring from an aromatic hydrocarbon is also referred to as an "aryl group". A group obtained by removing 2 hydrogen atoms directly bonded to atoms constituting a ring from an aromatic hydrocarbon is also referred to as "arylene".

The number of carbon atoms of the aromatic hydrocarbon group is usually 6 to 60, preferably 6 to 40, more preferably 6 to 20, excluding the number of carbon atoms of the substituent.

Examples of the "aromatic hydrocarbon group" include groups obtained by removing 1 or more hydrogen atoms directly bonded to atoms constituting a ring from a single-ring aromatic hydrocarbon (for example, benzene) or a multi-ring aromatic hydrocarbon (for example, a two-ring aromatic hydrocarbon such as naphthalene and indene, a three-ring aromatic hydrocarbon such as anthracene, phenanthrene, dihydrophenanthrene and fluorene, a four-ring aromatic hydrocarbon such as benzanthracene, benzophenanthrene, benzofluorene, pyrene and fluoranthene, a five-ring aromatic hydrocarbon such as dibenzoanthracene, dibenzophenanthrene, dibenzofluorene, perylene and benzofluoranthene, a six-ring aromatic hydrocarbon such as spirobifluorene, and a seven-ring aromatic hydrocarbon such as benzospirobifluorene and acenaphthylene. The aromatic hydrocarbon group includes a group in which a plurality of these groups are bonded. The aromatic hydrocarbon group may have a substituent.

"alkoxy" can be any of straight chain and branched. The number of carbon atoms of the straight-chain alkoxy group is usually 1 to 40, preferably 1 to 10, excluding the number of carbon atoms of the substituent. The number of carbon atoms of the branched alkoxy group is usually 3 to 40, preferably 4 to 10, excluding the number of carbon atoms of the substituent.

The alkoxy group may have a substituent. Examples of the alkoxy group include methoxy, ethoxy, isopropoxy, butoxy, hexyloxy, 2-ethylhexyloxy, 3, 7-dimethyloctyloxy and lauryloxy.

The number of carbon atoms of the "cycloalkoxy group" is usually 3 to 40, preferably 4 to 10, excluding the number of carbon atoms of the substituent. The cycloalkoxy group may have a substituent. Examples of the cycloalkoxy group include cyclohexyloxy group.

The number of carbon atoms of the "aryloxy group" is usually 6 to 60, preferably 6 to 40, more preferably 6 to 20, excluding the number of carbon atoms of the substituent. The aryloxy group may have a substituent. Examples of the aryloxy group include a phenoxy group, a naphthoxy group, an anthracenoxy group and a pyrenyloxy group.

"heterocyclic group" means a group obtained by removing 1 or more hydrogen atoms directly bonded to atoms constituting a ring from a heterocyclic compound. Among the heterocyclic groups, preferred is an "aromatic heterocyclic group" which is a group obtained by removing 1 or more hydrogen atoms directly bonded to atoms constituting the ring from an aromatic heterocyclic compound. A group obtained by removing p hydrogen atoms (p represents an integer of 1 or more) directly bonded to an atom constituting a ring from a heterocyclic compound is also referred to as a "p-valent heterocyclic group". A group obtained by removing p hydrogen atoms directly bonded to atoms constituting a ring from an aromatic heterocyclic compound is also referred to as a "p-valent aromatic heterocyclic group".

Examples of the "aromatic heterocyclic compound" include compounds in which the heterocyclic ring itself such as oxazole, thiophene, furan, pyridine, diazabenzene, triazine, naphthyridine and carbazole shows an aromatic character, and compounds in which the heterocyclic ring itself such as phenoxazine, phenothiazine and benzopyran does not show an aromatic character but has an aromatic ring fused to the heterocyclic ring.

The number of carbon atoms of the heterocyclic group is usually 1 to 60, preferably 2 to 40, more preferably 3 to 20, excluding the number of carbon atoms of the substituent. The number of heteroatoms of the aromatic heterocyclic group excluding the number of heteroatoms of the substituent is usually 1 to 30, preferably 1 to 10, more preferably 1 to 5, still more preferably 1 to 3.

Examples of the heterocyclic group include: from the monocyclic heterocyclic compounds (for example, furan, thiophene, oxadiazole, pyrrole, diazole, triazole, tetrazole, pyridine, diazabenzene and triazine) or polycyclic heterocyclic compounds (for example, naphthyridine, benzofuran, benzothiophene, indole, benzodiazole and benzothiadiazole and other bicyclic heterocyclic compounds; three-ring heterocyclic compounds such as dibenzofuran, dibenzothiophene, dibenzoborone, dibenzosilole, dibenzophosphole, dibenzoselenophene, carbazole, azacarbazole, diazacarbazole, phenoxazine, phenothiazine, 9, 10-dihydroacridine, 5, 10-dihydrophenazine, 9-aza-10-boroxine (Japanese) or 9-aza-10-phosphaanthracene (Phenophosazine), phenoselenazine (Phenoselenzazine), 9-aza-10-silaxanthene (Phenazasiline), azaanthracene, diazaanthracene, azaphenanthrene, and diazaphenanthrene; four-ring heterocyclic compounds such as hexaazabenzophenanthrene, benzocarbazole, benzonaphthofuran and benzonaphthothiophene, five-ring heterocyclic compounds such as dibenzocarbazole, indolocarbazole and indenocarbazole, six-ring heterocyclic compounds such as carbazole, benzoindolocarbazole and benzoindenocarbazole, and seven-ring heterocyclic compounds such as dibenzoindolocarbazole) are used to remove 1 or more hydrogen atoms directly bonded to the atoms constituting the ring. Heterocyclic groups include groups in which a plurality of these groups are bonded. The heterocyclic group may have a substituent.

"halogen atom" means a fluorine atom, a chlorine atom, a bromine atom or an iodine atom.

The "amino group" may have a substituent, and is preferably a substituted amino group (i.e., a secondary amino group or a tertiary amino group, more preferably a tertiary amino group). The substituent of the amino group is preferably an alkyl group, a cycloalkyl group, an aryl group or a monovalent heterocyclic group. The substituents of the amino group may be the same or different in the case where there are plural, and may be bonded to each other to form a ring together with the nitrogen atom to which each is bonded.

Examples of the substituted amino group include a dialkylamino group, a dicycloalkylamino group, and a diarylamino group.

Examples of the amino group include a dimethylamino group, a diethylamino group, a diphenylamino group, a bis (methylphenyl) amino group, and a bis (3, 5-di-t-butylphenyl) amino group.

"alkenyl" may be any of straight chain and branched. The number of carbon atoms of the straight-chain alkenyl group is usually 2 to 30, preferably 3 to 20, excluding the number of carbon atoms of the substituent. The number of carbon atoms of the branched alkenyl group is usually 3 to 30, preferably 4 to 20, excluding the number of carbon atoms of the substituent.

The number of carbon atoms of the "cycloalkenyl group" is usually 3 to 30, preferably 4 to 20, excluding the number of carbon atoms of the substituent.

Alkenyl and cycloalkenyl groups may have substituents. Examples of the alkenyl group include a vinyl group, a 1-propenyl group, a 2-butenyl group, a 3-pentenyl group, a 4-pentenyl group, a 1-hexenyl group, a 5-hexenyl group, a 7-octenyl group, and a group in which a part or all of hydrogen atoms in these groups are substituted with a substituent. Examples of the cycloalkenyl group include a cyclohexenyl group, a cyclohexadienyl group, a cyclooctatrienyl group, a norbornenyl group, and a group in which a part or all of hydrogen atoms in these groups are substituted with a substituent.

"alkynyl" can be any of straight and branched. The number of carbon atoms of the alkynyl group excluding the carbon atoms of the substituent is usually 2 to 20, preferably 3 to 20. The number of carbon atoms of the branched alkynyl group is usually 4 to 30, preferably 4 to 20, excluding the carbon atoms of the substituent.

The number of carbon atoms of the "cycloalkynyl group" is usually 4 to 30, preferably 4 to 20, excluding the carbon atoms of the substituent.

Alkynyl and cycloalkynyl groups may have substituents. Examples of the alkynyl group include an ethynyl group, a 1-propynyl group, a 2-butynyl group, a 3-pentynyl group, a 4-pentynyl group, a 1-hexynyl group, a 5-hexynyl group, and a group in which a part or all of hydrogen atoms in these groups are substituted with a substituent. Examples of the cycloalkynyl group include cyclooctyl group.

The "crosslinking group" means a group capable of generating a new bond by being subjected to heating, ultraviolet irradiation, near ultraviolet irradiation, visible light irradiation, infrared irradiation, radical reaction, or the like. The crosslinking group is preferably a crosslinking group selected from the group A of crosslinking groups (i.e., a group represented by any of the formulae (XL-1) to (XL-19)).

(Cross-linking group A)

[ chemical formula 10]

[ formula, R ^XL Represents a methylene group, an oxygen atom or a sulfur atom, n ^XL An integer of 0 to 5. R is R ^XL Where there are plural, they may be the same or different. A plurality of n ^XL May be the same or different. *1 represents a bonding position. These crosslinking groups may have a substituent. Where there are plural substituents, they may be the same or different and may be bonded to each other to form a ring together with the carbon atom to which each is bonded.]

Examples of the "substituent" include a halogen atom, cyano group, alkyl group, cycloalkyl group, aryl group, monovalent heterocyclic group, alkoxy group, cycloalkoxy group, aryloxy group, amino group, substituted amino group, alkenyl group, cycloalkenyl group, alkynyl group, and cycloalkynyl group. The substituent may be a crosslinking group. In the case where a plurality of substituents are present, they may be bonded to each other to form a ring together with the atoms to which each is bonded, but preferably do not form a ring.

In the present specification, the absolute value of the difference between the energy level of the lowest triplet excited state and the energy level of the lowest singlet excited state (hereinafter also referred to as "Δe _ST ") is calculated by the following method. First, the ground state of the compound was structurally optimized using the density functional method at the B3LYP level. In this case, 6-31G was used as the basis function. Then, using the resulting structure-optimized structure, the ΔE of the compound was calculated using a time-dependent density functional method of B3LYP levels _ST . Wherein, in the case of containing an atom for which 6-31G is not available, LANL2DZ is used for the atom. As a quantum chemical calculation program, calculation was performed using Gaussian 09.

Composition for light-emitting element

The composition for a light-emitting element of the present embodiment contains a metal complex represented by formula (2) and a compound (B) having a condensed heterocyclic skeleton (B).

In the composition for a light-emitting element of the present embodiment, each of the metal complex represented by the formula (2) and the compound (B) may contain only 1 species or may contain 2 or more species.

In the composition for a light-emitting element of the present embodiment, the metal complex represented by formula (2) and the compound (B) preferably physically, chemically or electrically interact. By this interaction, for example, the light-emitting property, the charge transport property, or the charge injection property of the composition for a light-emitting element of the present embodiment can be improved or adjusted.

In the composition for a light-emitting element of the present embodiment, a light-emitting material will be described as an example, and in this case, the metal complex represented by the formula (2) and the compound (B) electrically interact with each other, and electric energy is efficiently transferred from the compound (B) to the metal complex represented by the formula (2), whereby the metal complex represented by the formula (2) can be made to emit light more efficiently, and the light-emitting element of the present embodiment is further excellent in light-emitting efficiency.

From the above point of view, for the reason that the light-emitting element of the present embodiment is more excellent in light-emitting efficiency, the lowest excited triplet state (T ₁ ) Preferably has a lowest excited triplet state (T) than the metal complex represented by formula (2) ₁ ) Higher energy levels.

In the composition for a light-emitting element of the present embodiment, the content of the metal complex represented by the formula (2) is usually 0.1 to 99.9 parts by mass, based on 100 parts by mass of the total of the compound (B) and the metal complex represented by the formula (2), and for the reason that the light-emitting element of the present embodiment is more excellent in light-emitting efficiency, it is preferably 1 to 99 parts by mass, more preferably 10 to 97 parts by mass, still more preferably 30 to 95 parts by mass, particularly preferably 50 to 90 parts by mass, and particularly preferably 70 to 90 parts by mass.

[ Compound (B) ]

The compound (B) has a ring containing a boron atom and a member selected from the group consisting of an oxygen atom, a sulfur atom,Selenium atom, sp ³ A compound having a condensed heterocyclic skeleton of at least 1 of a carbon atom and a nitrogen atom.

In the compound (B), when the condensed heterocyclic skeleton (B) contains nitrogen atoms, at least 1 of the nitrogen atoms contained in the condensed heterocyclic skeleton (B) is preferably a nitrogen atom not forming a double bond, and more preferably, the nitrogen atoms contained in the condensed heterocyclic skeleton (B) are all nitrogen atoms not forming a double bond.

The number of carbon atoms of the condensed heterocyclic skeleton (b) excluding the number of carbon atoms of the substituent is usually 1 to 60, preferably 5 to 40, more preferably 10 to 25.

The number of heteroatoms of the condensed heterocyclic skeleton (b) excluding the number of heteroatoms of the substituent is usually 2 to 30, preferably 2 to 15, more preferably 2 to 10, still more preferably 2 to 5, particularly preferably 2 or 3.

The number of boron atoms of the condensed heterocyclic skeleton (b) excluding the number of boron atoms of the substituent is usually 1 to 10, preferably 1 to 5, more preferably 1 to 3, still more preferably 1.

An oxygen atom, a sulfur atom, a selenium atom, an sp of the condensed heterocyclic skeleton (b) ³ The total number of carbon atoms and nitrogen atoms excluding the number of atoms of the substituent is usually 1 to 20, preferably 1 to 10, more preferably 1 to 5, still more preferably 1 to 3, particularly preferably 2.

For the reason that the light-emitting element of the present embodiment is more excellent in light-emitting efficiency, the condensed heterocyclic skeleton (b) preferably contains a boron atom and at least 1 selected from an oxygen atom, a sulfur atom and a nitrogen atom in the ring, more preferably contains a boron atom and a nitrogen atom in the ring, and even more preferably contains a boron atom and a nitrogen atom that does not form a double bond in the ring.

The condensed heterocyclic skeleton (b) is preferably a tricyclo-dodecacyclic condensed heterocyclic skeleton, more preferably a tricyclo-hexacyclic condensed heterocyclic skeleton, and still more preferably a pentacyclic condensed heterocyclic skeleton, for the reason that the light-emitting element of the present embodiment is more excellent in light-emitting efficiency.

The condensed heterocyclic skeleton (b) may also be referred to as a compound having a heterocyclic group (b') containing the condensed heterocyclic skeleton (b).

The heterocyclic group (b') may be selected from the group consisting of a boron atom and an oxygen atom, a sulfur atom, a selenium atom, an sp ³ The polycyclic heterocyclic compound having at least 1 of a carbon atom and a nitrogen atom may have a substituent, and a group having 1 or more hydrogen atoms directly bonded to atoms constituting the ring is removed. In the heterocyclic group (b'), the polycyclic heterocyclic compound is preferably a polycyclic heterocyclic compound containing a boron atom and at least 1 selected from an oxygen atom, a sulfur atom and a nitrogen atom in the ring, more preferably a polycyclic heterocyclic compound containing a boron atom and a nitrogen atom in the ring, and still more preferably a polycyclic heterocyclic compound containing a boron atom and a nitrogen atom not forming a double bond in the ring. In the heterocyclic group (b'), the polycyclic heterocyclic compound is preferably a tricyclic to twelve-membered heterocyclic compound, more preferably a tricyclic to six-membered heterocyclic compound, and still more preferably a pentacyclic heterocyclic compound.

The substituent which the heterocyclic group (b') may have is preferably a halogen atom, cyano group, alkyl group, cycloalkyl group, alkoxy group, cycloalkoxy group, aryl group, monovalent heterocyclic group or substituted amino group, more preferably alkyl group, cycloalkyl group, alkoxy group, cycloalkoxy group, aryl group, monovalent heterocyclic group or substituted amino group, further preferably alkyl group, aryl group or substituted amino group, and these groups may further have a substituent.

Among the substituents that the heterocyclic group (b') may have, the aryl group is preferably a group in which 1 hydrogen atom directly bonded to an atom constituting a ring is removed from a monocyclic or bicyclic to six-ring aromatic hydrocarbon, more preferably a group in which 1 hydrogen atom directly bonded to an atom constituting a ring is removed from a monocyclic, bicyclic or three-ring aromatic hydrocarbon, still more preferably a group in which 1 hydrogen atom directly bonded to an atom constituting a ring is removed from benzene, naphthalene, anthracene, phenanthrene or fluorene, particularly preferably a phenyl group, and these groups may have substituents.

Among the substituents that the heterocyclic group (b') may have, the monovalent heterocyclic group is preferably a group in which 1 hydrogen atom directly bonded to a ring-constituting atom is removed from a monocyclic or bicyclic to six-ring heterocyclic compound, more preferably a group in which 1 hydrogen atom directly bonded to a ring-constituting atom is removed from a monocyclic, bicyclic or tricyclic heterocyclic compound, still more preferably a group in which 1 hydrogen atom directly bonded to a ring-constituting atom is removed from pyridine, diazabenzene, triazine, azanaphthalene, naphthyridine, carbazole, dibenzofuran, dibenzothiophene, phenoxazine or phenothiazine, particularly preferably a group in which 1 hydrogen atom directly bonded to a ring-constituting atom is removed from pyridine, diazabenzene or triazine, and these groups may have a substituent.

Among the substituents that the heterocyclic group (b') may have, the substituent that the amino group has is preferably an aryl group or a monovalent heterocyclic group, more preferably an aryl group, and these groups may further have a substituent. Examples and preferable ranges of the aryl group and the monovalent heterocyclic group in the substituent of the amino group are the same as those of the aryl group and the monovalent heterocyclic group in the substituent which the heterocyclic group (b') may have.

The substituent which may be further substituted by the heterocyclic group (b') is preferably a halogen atom, an alkyl group, a cycloalkyl group, an alkoxy group, a cycloalkoxy group, an aryl group, a monovalent heterocyclic group or a substituted amino group, more preferably an alkyl group, a cycloalkyl group, an aryl group, a monovalent heterocyclic group or a substituted amino group, further preferably an alkyl group or a cycloalkyl group, and these groups may be further substituted, but preferably do not further have a substituent.

Examples and preferable ranges of the aryl group, the monovalent heterocyclic group, and the substituted amino group in the substituent which the heterocyclic group (b ') may have may further have are the same as those of the aryl group, the monovalent heterocyclic group, and the substituted amino group in the substituent which the heterocyclic group (b') may have.

"nitrogen atom not forming a double bond" means a nitrogen atom bonded to the other 3 atoms by single bonds, respectively.

"containing a nitrogen atom in the ring that does not form a double bond" means that the ring contains-N (-R) ^N ) - (wherein R is ^N Represents a hydrogen atom or a substituent. ) Or a group represented by the following formula.

[ chemical formula 11]

The compound (B) is preferably a Thermally Active Delayed Fluorescence (TADF) compound for the reason that the light-emitting element of the present embodiment is more excellent in light-emitting efficiency.

ΔE of Compound (B) _ST The light-emitting element of the present embodiment may have a light-emitting efficiency of 2.0eV or less, 1.5eV or less, 1.0eV or less, 0.80eV or less, or 0.60eV or less, and preferably 0.50eV or less, for reasons of more excellent light-emitting efficiency. In addition, ΔE of Compound (B) _ST The amount may be 0.001eV or more, or 0.01eV or more, or 0.10eV or more, or 0.20eV or more, or 0.30eV or more, or 0.40eV or more.

The compound (B) is preferably a low molecular compound.

The molecular weight of the compound (B) is preferably 1X 10 ² ～5×10 ³ More preferably 2X 10 ² ～3×10 ³ More preferably 3X 10 ² ～1.5×10 ³ Particularly preferably 4X 10 ² ～1×10 ³ 。

For the reason that the light-emitting element of the present embodiment is more excellent in light-emitting efficiency, the compound (B) is preferably a compound represented by formula (1-1), formula (1-2) or formula (1-3), more preferably a compound represented by formula (1-2) or formula (1-3), and still more preferably a compound represented by formula (1-2).

Ar ¹ 、Ar ² And Ar is a group ³ For the reason that the light-emitting element of the present embodiment is more excellent in light-emitting efficiency, it is preferable to remove 1 or more hydrogen atoms directly bonded to atoms constituting the ring from a single-ring, double-ring or triple-ring aromatic hydrocarbon or a single-ring, double-ring or triple-ring heterocyclic compound, more preferable to remove 1 or more hydrogen atoms directly bonded to atoms constituting the ring from a single-ring aromatic hydrocarbon or a single-ring heterocyclic compound, and still more preferableIn order to remove 1 or more hydrogen atoms directly bonded to atoms constituting the ring from benzene, pyridine or diazabenzene, it is particularly preferable to remove 1 or more hydrogen atoms directly bonded to atoms constituting the ring from benzene, and these groups may have a substituent.

Ar ¹ 、Ar ² And Ar is a group ³ Examples and preferable ranges of the substituents which may be present are the same as those of the substituents which may be present in the heterocyclic group (b').

Y ¹ Preferably an oxygen atom, a sulfur atom, -N (Ry) -shown group or a methylene group, more preferably an oxygen atom, a sulfur atom or-N (Ry) -shown group, further preferably-N (Ry) -shown group, which may have a substituent.

Y ² And Y ³ Preferably a single bond, an oxygen atom, a sulfur atom, -N (Ry) -represented group or a methylene group, more preferably a single bond, an oxygen atom, a sulfur atom or-N (Ry) -represented group, further preferably an oxygen atom, a sulfur atom or-N (Ry) -represented group, particularly preferably-N (Ry) -represented group, which may have a substituent.

For reasons that the light-emitting element of the present embodiment is more excellent in light-emitting efficiency, Y is preferable ¹ 、Y ² And Y ³ Are each an oxygen atom, a sulfur atom or a group represented by-N (Ry) -more preferably Y ¹ 、Y ² And Y ³ Are all-N (Ry) -groups.

Y ¹ 、Y ² And Y ³ Examples and preferable ranges of the substituents which may be present are the same as those of the substituents which may be present in the heterocyclic group (b').

Ry is preferably an alkyl group, a cycloalkyl group, an aryl group or a monovalent heterocyclic group, more preferably an aryl group or a monovalent heterocyclic group, further preferably an aryl group, and these groups may have a substituent.

Examples and preferable ranges of the aryl group and the monovalent heterocyclic group in Ry are the same as those of the aryl group and the monovalent heterocyclic group in the substituent which the heterocyclic group (b') may have, respectively.

Examples and preferable ranges of the substituent that Ry may have are the same as those of the substituent that heterocyclyl (b') may have.

Ry may be bonded to Ar directly or via a linking group ¹ 、Ar ² Or Ar ³ Bonded, but preferably not bonded. Examples of the linking group include: -O-indicated groups, -S-indicated groups, -N (Ry) -indicated groups, alkylene, cycloalkylene, arylene and divalent heterocyclic groups, preferably-O-indicated groups, -S-indicated groups, -N (Ry) -indicated groups or methylene groups, which groups may have substituents.

The compound (B) is exemplified by a compound represented by the following formula and compounds B1 to B3 described later.

[ chemical formula 12]

[ chemical formula 13]

Wherein Z is ¹ Represents an oxygen atom or a sulfur atom.

[ Metal Complex represented by the formula (2) ]

The metal complex represented by the formula (2) is usually a metal complex exhibiting phosphorescence at room temperature, and preferably a metal complex exhibiting luminescence from a triplet excited state at room temperature.

The maximum peak wavelength of the emission spectrum of the metal complex represented by the formula (2) is preferably 495nm to 750nm, more preferably 500nm to 680nm, still more preferably 505nm to 660nm, particularly preferably 510nm to 640 nm.

The maximum peak wavelength of the luminescence spectrum of the metal complex can be obtained by dissolving the metal complex in an organic solvent such as xylene, toluene, chloroform, tetrahydrofuran, etc., to prepare a dilute solution (1×10) ^-6 ～1×10 ^-3 Mass%) of the diluted solution was measured at room temperature to evaluate the PL spectrum. As the organic solvent for dissolving the metal complex, xylene is preferable.

M ² For the reason that the light-emitting element of the present embodiment is more excellent in light-emitting efficiency, an iridium atom or a platinum atom is preferable, and an iridium atom is more preferable.

At M ² In the case of rhodium or iridium atoms, n ³ Preferably 2 or 3, more preferably 3.

At M ² In the case of palladium or platinum atoms, n ³ Preferably 2.

E ^L Preferably a carbon atom. E (E) ^L Where there are plural, they are preferably the same.

Ring L ¹ The number of carbon atoms of the aromatic heterocycle including a six-membered ring is usually 1 to 60, preferably 2 to 30, more preferably 3 to 15, excluding the number of carbon atoms of the substituent. As ring L ¹ Examples of the aromatic heterocyclic ring having a six-membered ring include aromatic heterocyclic rings having a nitrogen atom in the ring and having a six-membered ring among aromatic heterocyclic rings included in the aromatic heterocyclic compounds exemplified in the foregoing items of heterocyclic groups.

Ring L ¹ For the reason that the light-emitting element of the present embodiment is more excellent in light-emitting efficiency, an aromatic heterocycle having 1 or more and 4 or less nitrogen atoms as constituent atoms and containing a six-membered ring is preferable, a pyridine ring, a diazabenzene ring, an azanaphthalene ring or a naphthyridine ring is more preferable, a pyridine ring, a quinoline ring or an isoquinoline ring is more preferable, a pyridine ring or a quinoline ring is particularly preferable, and a pyridine ring is particularly preferable, and these rings may have a substituent.

For the reason that the metal complex represented by formula (2) can be easily synthesized, the ring L ¹ In the case where there are plural, plural rings L are present ¹ Among them, preferably at least 2 are identical, more preferably a plurality of rings L are present ¹ All the same.

Ring L ² The number of carbon atoms of the aromatic hydrocarbon ring not including the substituentGenerally, the content is 6 to 60, preferably 6 to 30, and more preferably 6 to 18.

As ring L ² Examples of the aromatic hydrocarbon ring include aromatic hydrocarbon rings included in the aromatic hydrocarbons exemplified in the above-mentioned items of aromatic hydrocarbon groups.

Ring L ² The aromatic hydrocarbon ring in (a) is preferably a monocyclic, bicyclic or tricyclic aromatic hydrocarbon ring, more preferably a benzene ring, naphthalene ring, fluorene ring, phenanthrene ring or dihydrophenanthrene ring, still more preferably a benzene ring, fluorene ring or dihydrophenanthrene ring, particularly preferably a benzene ring, and these rings may have a substituent.

Ring L ² The number of carbon atoms of the aromatic heterocycle excluding the number of carbon atoms of the substituent is usually 1 to 60, preferably 2 to 30, more preferably 3 to 15. Ring L ² The number of heteroatoms of the aromatic heterocycle excluding the number of heteroatoms of the substituent is usually 1 to 30, preferably 1 to 10, more preferably 1 to 3.

As ring L ² Examples of the aromatic heterocyclic ring include aromatic heterocyclic rings included in the aromatic heterocyclic compounds exemplified in the items of the heterocyclic groups described above.

Ring L ² The aromatic heterocyclic ring in (a) is preferably a monocyclic, bicyclic or tricyclic aromatic heterocyclic ring, more preferably a pyridine ring, a diazabenzene ring, an azanaphthalene ring, a naphthyridine ring, an indole ring, a benzofuran ring, a benzothiophene ring, a carbazole ring, an azacarbazole ring, a diazacarbazole ring, a dibenzofuran ring or a dibenzothiophene ring, still more preferably a pyridine ring, a diazabenzene ring, a carbazole ring, a dibenzofuran ring or a dibenzothiophene ring, particularly preferably a pyridine ring or a diazabenzene ring, and these rings may have a substituent.

Ring L ² For the reason that the light-emitting element of the present embodiment is more excellent in light-emitting efficiency, a benzene ring, a pyridine ring, or a diazabenzene ring is preferable, a benzene ring is more preferable, and these rings may have a substituent.

For the reason that the metal complex represented by formula (2) can be easily synthesized, the ring L ² In the case where there are plural, plural rings L are present ² Among these, the group consisting of the above-mentioned materials,preferably at least 2 identical, more preferably present, rings L ² All the same.

For reasons that the light-emitting element of the present embodiment is more excellent in light-emitting efficiency, the ring L is preferable ¹ Is a pyridine ring, a diazabenzene ring, an azanaphthalene ring or a naphthyridine ring, and a ring L ² Is a benzene ring, a pyridine ring or a diazabenzene ring, more preferably a ring L ¹ Is a pyridine ring, a quinoline ring or an isoquinoline ring and the ring L ² Is a benzene ring, further preferred is ring L ¹ Is a pyridine ring or a quinoline ring and the ring L ² Is a benzene ring, particularly preferred is ring L ¹ Is a pyridine ring and the ring L ² Is benzene ring. These rings may have a substituent.

"Ring L ¹ And ring L ² Wherein at least 1 group of the formula (1-T) is a substituent "means that a ring L is constituted ¹ And ring L ² The group represented by the formula (1-T) is directly bonded to at least 1 atom (preferably a carbon atom or a nitrogen atom).

In the metal complex represented by the formula (2), the ring L ¹ And ring L ² In the case where there are plural, plural rings L are present ¹ And ring L ² At least 1 ring among them may have a group represented by the formula (1-T), and for reasons that the light-emitting element of the present embodiment is more excellent in light-emitting efficiency, a plurality of rings L are preferably present ¹ Each having a group represented by the formula (1-T) and a plurality of rings L present ² Each having a group represented by the formula (1-T) or a plurality of rings L present ¹ And ring L ² Each having a group represented by the formula (1-T), more preferably a plurality of rings L present ¹ Each having a group represented by the formula (1-T) or a plurality of rings L present ² All have the group represented by the formula (1-T).

In the metal complex represented by the formula (2), the ring L ¹ And ring L ² The number of the groups represented by the formula (1-T) is usually 1 to 5, and for the reason that the metal complex represented by the formula (2) can be easily synthesized, it is preferably 1 to 3, more preferably 1 or 2, and even more preferably 1.

In the metal complex represented by the formula (2), M is ² In the case of rhodium or iridium atoms, the ring L ¹ And ring L ² The total number of the groups represented by the formula (1-T) is usually 1 to 30, and for the reason that the light-emitting element of the present embodiment is more excellent in light-emitting efficiency, it is preferably 1 to 18, more preferably 2 to 12, and even more preferably 3 to 6.

In the metal complex represented by the formula (2), M is ² In the case of palladium or platinum atoms, the ring L ¹ And ring L ² The total number of the groups represented by the formula (1-T) is usually 1 to 20, and for reasons of more excellent luminous efficiency of the light-emitting element of the present embodiment, it is preferably 1 to 12, more preferably 1 to 8, and even more preferably 2 to 4.

Ring L ¹ And ring L ² The substituent that may be included is preferably a group represented by the formula (1-T) for the reason that the light-emitting element of the present embodiment is more excellent in light-emitting efficiency.

Ring L ¹ And ring L ² Among the substituents which may be provided, a cyano group, an alkenyl group or a cycloalkenyl group is preferable as a substituent other than the group represented by the formula (1-T), and these groups may further have a substituent. Examples of substituents which may be further contained in the substituent other than the group represented by the formula (1-T) and preferable ranges thereof are as follows ^1T Examples of substituents which may be present are the same as the preferred ranges.

[ group of formula (1-T) ]

As R ^1T The aryl group in (a) is preferably a group obtained by removing 1 hydrogen atom directly bonded to a ring-constituting atom from a monocyclic, bicyclic or tricyclic aromatic hydrocarbon, more preferably a phenyl group, a naphthyl group or a fluorenyl group, still more preferably a phenyl group, and these groups may have a substituent.

As R ^1T The monovalent heterocyclic group in (a) is preferably a group obtained by removing 1 hydrogen atom directly bonded to the atom constituting the ring from a monocyclic, bicyclic or tricyclic heterocyclic compound, more preferably a group obtained by removing 1 hydrogen atom directly bonded to the atom constituting the ring from pyridine, diazabenzene, triazine, azanaphthalene, diazanaphthalene, carbazole, dibenzofuran or dibenzothiophene The group having 1 hydrogen atom bonded thereto is more preferably a group having 1 hydrogen atom directly bonded to an atom constituting a ring removed from pyridine, diazabenzene or triazine, and these groups may have a substituent.

R ^1T The substituent of the amino group in (a) is preferably an aryl group or a monovalent heterocyclic group, more preferably an aryl group, and these groups may further have a substituent. Examples and preferred ranges of aryl groups as substituents of amino groups and R ^1T The examples and preferred ranges of aryl groups in (a) are the same. Examples and preferred ranges of monovalent heterocyclic groups as substituents of amino groups and R ^1T Examples of the monovalent heterocyclic group in (a) and the preferable range are the same.

Among at least 1 of the groups represented by the formula (1-T), R is preferable for the reason that the light-emitting element of the present embodiment is more excellent in light-emitting efficiency ^1T Is alkyl, cycloalkyl, aryl, monovalent heterocyclic or substituted amino, more preferably R ^1T Is aryl, monovalent heterocyclic or substituted amino, more preferably R ^1T Is aryl or monovalent heterocyclic, R being particularly preferred ^1T Aryl groups, these groups may have substituents.

Ring L ¹ In the case of an isoquinoline ring, R is preferable for the reason that the light-emitting element of the present embodiment is further excellent in light-emitting efficiency among at least 1 of the groups represented by the formula (1-T) ^1T Is aryl, monovalent heterocyclic or substituted amino, more preferably R ^1T Is aryl or monovalent heterocyclic, further preferably R ^1T Aryl groups, these groups may have substituents.

Ring L ¹ In the case of an aromatic heterocycle having a six-membered ring other than an isoquinoline ring (preferably a pyridine ring, a diazabenzene ring, a quinoline ring or a naphthyridine ring, more preferably a pyridine ring or a quinoline ring, further preferably a pyridine ring), R is preferably selected from at least 1 of the groups represented by the formula (1-T) for the reason that the light-emitting element of the present embodiment is further excellent in light-emitting efficiency ^1T Is alkyl, cycloalkyl, aryl, monovalent heterocyclic or substituted amino, more preferably R ^1T Is alkyl, cycloalkyl, aryl or monovalent heterocyclic group, furtherPreferably R ^1T Is aryl or monovalent heterocyclic, R being particularly preferred ^1T Aryl groups, these groups may have substituents.

R ^1T For the reason that the light-emitting element of the present embodiment is more excellent in light-emitting efficiency, an alkyl group, a cycloalkyl group, an aryl group, a monovalent heterocyclic group, or a substituted amino group is preferable, an aryl group, a monovalent heterocyclic group, or a substituted amino group is more preferable, an aryl group or a monovalent heterocyclic group is more preferable, an aryl group is particularly preferable, and these groups may have a substituent.

Ring L ¹ In the case of isoquinoline ring, R ^1T For the reason that the light-emitting element of the present embodiment is further excellent in light-emitting efficiency, an aryl group, a monovalent heterocyclic group, or a substituted amino group is preferable, an aryl group or a monovalent heterocyclic group is more preferable, an aryl group is further preferable, and these groups may have a substituent.

Ring L ¹ In the case of an aromatic heterocyclic ring containing a six-membered ring other than an isoquinoline ring (preferably a pyridine ring, a diazabenzene ring, a quinoline ring or a naphthyridine ring, more preferably a pyridine ring or a quinoline ring, still more preferably a pyridine ring), R ^1T For the reason that the light-emitting element of the present embodiment is further excellent in light-emitting efficiency, it is preferably an alkyl group, a cycloalkyl group, an aryl group, a monovalent heterocyclic group, or a substituted amino group, more preferably an alkyl group, a cycloalkyl group, an aryl group, or a monovalent heterocyclic group, still more preferably an aryl group or a monovalent heterocyclic group, particularly preferably an aryl group, and these groups may have a substituent.

As R ^1T The substituent which may be provided is preferably an alkyl group, a cycloalkyl group, an alkoxy group, a cycloalkoxy group, an aryl group, a monovalent heterocyclic group, a substituted amino group or a fluorine atom, more preferably an alkyl group, a cycloalkyl group, an aryl group, a monovalent heterocyclic group or a substituted amino group, further preferably an alkyl group, a cycloalkyl group or an aryl group, and these groups may further have a substituent.

R ^1T Examples and preferred ranges of the aryl group, monovalent heterocyclic group and substituted amino group in the substituent which may be present are respectively the same as R ^1T Examples and preferred ranges of the aryl group, monovalent heterocyclic group and substituted amino group in (a) are the same.

As R ^1T Can be provided withThe substituent may further have a substituent, preferably an alkyl group, a cycloalkyl group, an alkoxy group, a cycloalkoxy group, an aryl group, a monovalent heterocyclic group, a substituted amino group, or a fluorine atom, more preferably an alkyl group, a cycloalkyl group, an aryl group, a monovalent heterocyclic group, or a substituted amino group, further preferably an alkyl group or a cycloalkyl group, which may further have a substituent, but preferably may not further have a substituent.

R ^1T Examples and preferred ranges of the aryl group, monovalent heterocyclic group and substituted amino group in the substituent which may be further substituted are respectively the same as those of R ^1T Examples and preferred ranges of the aryl group, monovalent heterocyclic group and substituted amino group in (a) are the same.

[ anionic bidentate ligand ]

As A ³ －G ² －A ⁴ The anionic bidentate ligand shown in the following formula may be exemplified. Wherein A is ³ －G ² －A ⁴ The anionic bidentate ligands shown and the suffix n ³ The number of ligands defined is different.

[ chemical formula 14]

Wherein, represents and M ² Bonding sites.

Examples of the metal complex represented by the formula (2) include metal complexes represented by the following formula, metal complexes G2 to G4 described below, and metal complexes R3 to R7 described below.

[ chemical formula 15]

[ chemical formula 16]

[ host Material ]

For the reason that the light-emitting element of the present embodiment is more excellent in light-emitting efficiency, the composition for a light-emitting element of the present embodiment preferably further includes a host material having at least 1 function selected from hole-injecting property, hole-transporting property, electron-injecting property and electron-transporting property. The composition for a light-emitting element of the present embodiment may contain only 1 kind of host material, or may contain 2 or more kinds. Wherein the host material is different from the compound (B). The host material is different from the metal complex represented by formula (2).

When the composition for a light-emitting element of the present embodiment further contains a host material, the total of the compound (B), the metal complex represented by the formula (2), and the host material is 100 parts by mass, and the content of the host material is usually 1 to 99.99 parts by mass, preferably 5 to 99.9 parts by mass, more preferably 10 to 99 parts by mass, still more preferably 30 to 97 parts by mass, particularly preferably 50 to 95 parts by mass, and particularly preferably 60 to 90 parts by mass.

When the composition for a light-emitting element of the present embodiment further contains a host material, the compound (B), and the metal complex represented by formula (2) preferably physically, chemically, or electrically interact. By this interaction, for example, the light-emitting property, the charge transport property, or the charge injection property of the composition for a light-emitting element of the present embodiment can be improved or adjusted.

In the case where the composition for a light-emitting element of the present embodiment further includes a host material, the light-emitting material will be described as an example, and in this case, the host material, the compound (B), and the metal complex represented by the formula (2) electrically interact with each other, and thus, electric energy is efficiently transferred from the host material to the compound (B), and further, electric energy is efficiently transferred from the compound (B) to the metal complex represented by the formula (2), whereby the metal complex represented by the formula (2) can be made to emit light more efficiently, and the light-emitting element of the present embodiment is more excellent in light-emitting efficiency.

From the above point of view, the light-emitting element according to the present embodiment has a lowest excited triplet state (T ₁ ) Preferably of the formula (2)The metal complex and the compound (B) have the lowest excited triplet state (T ₁ ) Higher energy levels. For reasons that the light-emitting element of the present embodiment is more excellent in light-emitting efficiency, the host material has a lowest excited singlet state (S ₁ ) Preferably a lowest excited singlet state (S) than that of the compound (B) ₁ ) Higher energy levels.

For the reason that the light-emitting element of the present embodiment can be produced by a wet method, a material which exhibits solubility in a solvent in which the metal complex represented by formula (2) and the compound (B) can be dissolved is preferable as the host material.

Host materials are classified into low molecular compounds (low molecular host) and high molecular compounds (high molecular host), and the composition for a light-emitting element according to the present embodiment may contain any of a variety of host materials. As the host material that can be contained in the composition for a light-emitting element of the present embodiment, a low-molecular compound is preferable for the reason that the light-emitting element of the present embodiment is more excellent in light-emitting efficiency.

Examples of the polymer body include a polymer compound as a hole transport material described below and a polymer compound as an electron transport material described below.

The low-molecular-weight host is preferably a compound represented by the formula (H-1) for reasons of more excellent light-emitting efficiency of the light-emitting element of the present embodiment. Here, the compound represented by the formula (H-1) is preferably a compound having no condensed heterocyclic skeleton (b) in the compound.

The molecular weight of the compound represented by the formula (H-1) is preferably 1X 10 ² ～5×10 ³ More preferably 2X 10 ² ～3×10 ³ More preferably 3X 10 ² ～1.5×10 ³ Particularly preferably 4X 10 ² ～1×10 ³ 。

Ar ^H1 And Ar is a group ^H2 The aryl group in (a) is preferably a group obtained by removing 1 hydrogen atom directly bonded to an atom constituting a ring from a monocyclic or bicyclic to hexacyclic aromatic hydrocarbon, more preferably a group obtained by removing a hydrogen atom directly bonded to an atom constituting a ring from a monocyclic or bicyclic to tetracyclic aromatic hydrocarbonThe group of 1 is more preferably a group obtained by removing 1 hydrogen atom directly bonded to an atom constituting a ring from benzene, naphthalene, fluorene, phenanthrene or triphenylene, and these groups may have a substituent.

L ^H1 The arylene group in (a) is preferably a group obtained by removing 2 hydrogen atoms directly bonded to atoms constituting the ring from a monocyclic or bicyclic to hexacyclic aromatic hydrocarbon, more preferably a group obtained by removing 2 hydrogen atoms directly bonded to atoms constituting the ring from a monocyclic or bicyclic to tetracyclic aromatic hydrocarbon, still more preferably a group obtained by removing 2 hydrogen atoms directly bonded to atoms constituting the ring from benzene, naphthalene, fluorene, phenanthrene or triphenylene, and these groups may have a substituent.

Ar ^H1 And Ar is a group ^H2 The monovalent heterocyclic group in (b) is preferably a group obtained by removing 1 hydrogen atom directly bonded to an atom constituting a ring from a heterocyclic compound not containing the condensed heterocyclic skeleton (b), and the group may have a substituent. Ar (Ar) ^H1 And Ar is a group ^H2 Examples of the monovalent heterocyclic group in (b) include heterocyclic compounds not containing a condensed heterocyclic skeleton (b), among the heterocyclic compounds described in the above items of heterocyclic groups, heterocyclic compounds not containing a boron atom and a nitrogen atom in the ring. Ar (Ar) ^H1 And Ar is a group ^H2 The monovalent heterocyclic group in (a) is preferably a group obtained by removing 1 hydrogen atom directly bonded to an atom constituting a ring from a monocyclic or bicyclic to six-membered heterocyclic compound (preferably a monocyclic or bicyclic to six-membered heterocyclic compound containing no condensed heterocyclic skeleton (b)), more preferably a group obtained by removing 1 hydrogen atom directly bonded to an atom constituting a ring from a monocyclic, bicyclic, tricyclic or pentacarbazole (preferably a monocyclic, bicyclic, tricyclic or pentacarbazole containing no condensed heterocyclic skeleton (b)), still more preferably a group obtained by removing 1 hydrogen atom directly bonded to an atom constituting a ring from a pyridine, diazabenzene, triazine, azanaphthalene, naphthyridine, carbazole, dibenzofuran, dibenzothiophene, phenoxazine, phenothiazine, dibenzocarbazole, indolocarbazole or indenocarbazole, particularly preferably a group obtained by removing 1 hydrogen atom directly bonded to an atom constituting a ring from a single, bicyclic, tricyclic or pentacarbazole Pyridine, diazabenzene, triazine, naphthyridine, carbazole, dibenzofuran or dibenzothiophene, which may have a substituent, are groups in which 1 hydrogen atom directly bonded to an atom constituting a ring is removed.

L ^H1 The divalent heterocyclic group in (b) is preferably a group obtained by removing 2 hydrogen atoms directly bonded to atoms constituting the ring from a heterocyclic compound not containing the condensed heterocyclic skeleton (b). L (L) ^H1 Examples of the divalent heterocyclic group in (b) include heterocyclic compounds not including a condensed heterocyclic skeleton (b), among the heterocyclic compounds described in the above items of heterocyclic groups, heterocyclic compounds not including a boron atom and a nitrogen atom in the ring. L (L) ^H1 The divalent heterocyclic group in (a) is preferably a group obtained by removing 2 hydrogen atoms directly bonded to atoms constituting a ring from a monocyclic or bicyclic to six-membered heterocyclic compound (preferably a monocyclic or bicyclic to six-membered heterocyclic compound not containing a condensed heterocyclic skeleton (b)), more preferably a group obtained by removing 2 hydrogen atoms directly bonded to atoms constituting a ring from a monocyclic, bicyclic, tricyclic or five-membered heterocyclic compound (preferably a monocyclic, bicyclic, tricyclic or five-membered heterocyclic compound not containing a condensed heterocyclic skeleton (b)), more preferred are groups obtained by removing 2 hydrogen atoms directly bonded to atoms constituting the ring from pyridine, diazabenzene, triazine, azanaphthalene, diazanaphthalene, carbazole, dibenzofuran, dibenzothiophene, phenoxazine, phenothiazine, dibenzocarbazole, indolocarbazole or indenocarbazole, and particularly preferred are groups obtained by removing 2 hydrogen atoms directly bonded to atoms constituting the ring from pyridine, diazabenzene, triazine, azanaphthalene, naphthyridine, carbazole, dibenzofuran or dibenzothiophene, and these groups may have a substituent.

Ar ^H1 And Ar is a group ^H2 The substituent of the amino group in (a) is preferably an aryl group or a monovalent heterocyclic group, more preferably an aryl group, and these groups may further have a substituent. Examples and preferred ranges of aryl groups as substituents of amino groups and Ar ^H1 And Ar is a group ^H2 Examples and advantages of aryl groups in (a)The selection ranges are the same. Examples and preferred ranges of monovalent heterocyclic groups as substituents of amino groups and Ar ^H1 And Ar is a group ^H2 Examples of the monovalent heterocyclic group in (a) and the preferable range are the same.

For reasons that the light-emitting element of the present embodiment is more excellent in light-emitting efficiency, ar ^H1 And Ar is a group ^H2 Preferably, at least 1 of them is an aryl group or a monovalent heterocyclic group, more preferably a monovalent heterocyclic group, further preferably a carbazolyl group, a dibenzothienyl group or a dibenzofuranyl group, particularly preferably a carbazolyl group, and these groups may have a substituent.

For reasons that the light-emitting element of the present embodiment is more excellent in light-emitting efficiency, ar ^H1 And Ar is a group ^H2 Aryl or monovalent heterocyclic group is preferable, more preferable is a group obtained by removing 1 hydrogen atom directly bonded to an atom constituting a ring from benzene, fluorene, pyridine, diazabenzene, triazine, carbazole, dibenzofuran or dibenzothiophene, further preferable is phenyl, fluorenyl, dibenzothienyl, dibenzofuranyl or carbazolyl, particularly preferable is carbazolyl, and these groups may have a substituent.

For reasons that the light-emitting element of the present embodiment is more excellent in light-emitting efficiency, L is preferable ^H1 At least 1 of these groups is an arylene group or a divalent heterocyclic group, more preferably a divalent heterocyclic group, further preferably a group obtained by removing 2 hydrogen atoms directly bonded to an atom (preferably a carbon atom) constituting a ring from carbazole, dibenzofuran or dibenzothiophene, and these groups may further have a substituent.

For reasons that the light-emitting element of the present embodiment is more excellent in light-emitting efficiency, L ^H1 Preferably an arylene group or a divalent heterocyclic group, more preferably a group in which 2 hydrogen atoms directly bonded to an atom (preferably a carbon atom) constituting a ring are removed from benzene, naphthalene, fluorene, pyridine, diazabenzene, triazine, azanaphthalene, diazanaphthalene, carbazole, dibenzofuran or dibenzothiophene, still more preferably a group in which 2 hydrogen atoms directly bonded to an atom (preferably a carbon atom) constituting a ring are removed from benzene, fluorene, pyridine, diazabenzene, triazine, carbazole, dibenzofuran or dibenzothiophene, particularly preferably a group in which 2 hydrogen atoms directly bonded to an atom (preferably a carbon atom) constituting a ring are removed from benzene, fluorene, pyridine, diazabenzene, triazine, carbazole, dibenzofuran or dibenzothiopheneSelected from the group consisting of 2 hydrogen atoms directly bonded to atoms constituting the ring, which may have a substituent, and a dibenzofuran or dibenzothiophene.

As Ar ^H1 、Ar ^H2 And L ^H1 The substituent which may be provided is preferably an alkyl group, a cycloalkyl group, an alkoxy group, a cycloalkoxy group, an aryl group, a monovalent heterocyclic group, a substituted amino group or a fluorine atom, more preferably an alkyl group, a cycloalkyl group, an aryl group, a monovalent heterocyclic group or a substituted amino group, further preferably an alkyl group, an aryl group or a monovalent heterocyclic group, and these groups may further have a substituent.

Ar ^H1 、Ar ^H2 And L ^H1 Examples and preferred ranges of the aryl group, monovalent heterocyclic group and substituted amino group in the substituents which may be present are each the same as Ar ^H1 And Ar is a group ^H2 Examples and preferred ranges of the aryl group, monovalent heterocyclic group and substituted amino group in (a) are the same.

As Ar ^H1 、Ar ^H2 And L ^H1 The substituent which may be further substituted is preferably an alkyl group, a cycloalkyl group, an aryl group, a monovalent heterocyclic group or a substituted amino group, more preferably an alkyl group or a cycloalkyl group, and these groups may be further substituted, but preferably do not further have a substituent.

Ar ^H1 、Ar ^H2 And L ^H1 Examples and preferred ranges of the aryl group, monovalent heterocyclic group and substituted amino group in the substituent which may have a substituent which may further have a substituent are each the same as Ar ^H1 And Ar is a group ^H2 Examples and preferred ranges of the aryl group, monovalent heterocyclic group and substituted amino group in (a) are the same.

n ^H1 Generally, the integer is 0 to 10, preferably 0 to 5, more preferably 1 to 3, and particularly preferably 1.

Examples of the compound represented by the formula (H-1) include compounds represented by the following formulas. In the formula, Z ¹ Represents an oxygen atom or a sulfur atom. Wherein Z is ² Represents a group represented by-ch=or a group represented by-n=.

[ chemical formula 17]

[ chemical formula 18]

[ other Components ]

The composition for a light-emitting element of the present embodiment may be a composition comprising the metal complex represented by formula (2), the compound (B), and at least 1 selected from the group consisting of the host material, the hole-transporting material, the hole-injecting material, the electron-transporting material, the electron-injecting material, the light-emitting material, the antioxidant, and the solvent. Wherein the hole transporting material, the hole injecting material, the electron transporting material, the electron injecting material and the light emitting material are different from the metal complex and the compound (B) shown in the formula (2).

[ ink ]

The composition (hereinafter referred to as "ink") containing the metal complex represented by formula (2), the compound (B), and the solvent is suitable for the production of a light-emitting element using a wet method such as spin coating, casting, micro gravure coating, bar coating, roll coating, wire bar coating, dip coating, spray coating, screen printing, flexographic printing, offset printing, inkjet printing, capillary coating, or nozzle coating. The viscosity of the ink may be adjusted according to the type of printing method, and is preferably 1 to 20 mPas at 25 ℃.

The solvent contained in the ink is preferably a solvent capable of dissolving or uniformly dispersing the solid components in the ink. Examples of the solvent include chlorine solvents, ether solvents, aromatic hydrocarbon solvents, aliphatic hydrocarbon solvents, ketone solvents, ester solvents, polyol solvents, alcohol solvents, sulfoxide solvents, and amide solvents.

The amount of the solvent to be blended in the ink is usually 1000 parts by mass to 10000000 parts by mass, based on 100 parts by mass of the total of the metal complex represented by the formula (2) and the compound (B).

The solvent may be used alone or in combination of two or more.

Hole transport material

The hole transport material is classified into a low molecular compound and a high molecular compound, and is preferably a high molecular compound having a crosslinking group.

Examples of the polymer compound include polyvinylcarbazole and derivatives thereof; polyarylene having an aromatic amine structure in a side chain or a main chain and derivatives thereof. The polymer compound may be a compound having an electron accepting moiety such as fullerene, tetrafluorotetracyanoquinodimethane, tetracyanoethylene, or trinitrofluorenone bonded thereto.

In the composition for a light-emitting element of the present embodiment, when the hole-transporting material is contained, the amount of the hole-transporting material is usually 1 to 10000 parts by mass based on 100 parts by mass of the total of the metal complex represented by the formula (2) and the compound (B).

The hole transport material may be used alone or in combination of two or more.

Electron transport material

Electron transport materials are classified into low molecular compounds and high molecular compounds. The electron transport material may have a crosslinking group.

Examples of the low molecular compound include metal complexes containing 8-hydroxyquinoline as a ligand, oxadiazoles, anthraquinone-dimethane, benzoquinone, naphthoquinone, anthraquinone, tetracyanoanthraquinone-dimethane, fluorenone, dicyanostilbene and diphenoquinone, and derivatives thereof.

Examples of the polymer compound include polyphenylene, polyfluorene, and derivatives thereof. The polymer compound may be doped with a metal.

In the composition for a light-emitting element of the present embodiment, when the electron-transporting material is contained, the amount of the electron-transporting material to be blended is usually 1 to 10000 parts by mass, based on 100 parts by mass of the total of the metal complex represented by the formula (2) and the compound (B).

The electron transport material may be used alone or in combination of two or more.

Hole injection material and electron injection material

The hole injecting material and the electron injecting material are each classified into a low molecular compound and a high molecular compound. The hole injecting material and the electron injecting material may have a crosslinking group.

Examples of the low-molecular compound include metal phthalocyanines such as copper phthalocyanine; carbon; metal oxides of molybdenum, tungsten, etc.; metal fluorides such as lithium fluoride, sodium fluoride, cesium fluoride, and potassium fluoride.

Examples of the polymer compound include polyaniline, polythiophene, polypyrrole, polyphenylene vinylene, polythiophene vinylene, polyquinoline, polyquinoxaline, and derivatives thereof; conductive polymers such as polymers containing an aromatic amine structure in the main chain or side chain.

In the composition for a light-emitting element of the present embodiment, when the hole injection material and/or the electron injection material are contained, the amount of the hole injection material and the electron injection material to be blended is usually 1 to 10000 parts by mass, based on 100 parts by mass of the total of the metal complex represented by the formula (2) and the compound (B).

The hole injecting material and the electron injecting material may be used singly or in combination.

Ion doping

When the hole injection material or the electron injection material contains a conductive polymer, the conductivity of the conductive polymer is preferably 1×10 ^-5 S/cm～1×10 ³ S/cm. In order to set the conductivity of the conductive polymer to this range, a proper amount of ions may be doped into the conductive polymer. The type of the doped ions is anionic in the case of a hole injection material, and cationic in the case of an electron injection material. Examples of the anions include polystyrene sulfonate ion, alkylbenzenesulfonate ion, and camphorsulfonate ion. Examples of the cations include lithium ion, sodium ion, potassium ion, and tetrabutylammonium ion.

The doping ions may be used alone or in combination of two or more.

Luminescent material

Luminescent materials are classified into low molecular compounds and high molecular compounds. The luminescent material may have a crosslinking group.

Examples of the low-molecular compound include naphthalene and its derivatives, anthracene and its derivatives, perylene and its derivatives, and triplet light-emitting complexes containing iridium, platinum, or europium as a central metal.

Examples of the triplet light emitting complex include the following metal complexes.

[ chemical formula 19]

Examples of the polymer compound include arylene groups including phenylene group, naphthalenediyl group, fluorenediyl group, phenanthrediyl group, dihydrophenanthrediyl group, anthracenediyl group, and pyrenediyl group; an aromatic amine residue such as a group obtained by removing 2 hydrogen atoms from an aromatic amine; and a polymer compound having a divalent heterocyclic group such as a carbazolyl group, a phenoxazinyl group and a phenothiazinyl group.

In the composition for a light-emitting element of the present embodiment, when the light-emitting material is contained, the content of the light-emitting material is usually 1 to 10000 parts by mass, based on 100 parts by mass of the total of the metal complex represented by the formula (2) and the compound (B).

The light-emitting material may be used alone or in combination of two or more.

Antioxidant(s)

The antioxidant may be a compound which is soluble in the same solvent as the metal complex represented by the formula (2) and the compound (B) and does not impair light emission or charge transport, and examples thereof include a phenol-based antioxidant and a phosphorus-based antioxidant.

In the composition for a light-emitting element of the present embodiment, when the antioxidant is contained, the amount of the antioxidant is usually 0.00001 to 10 parts by mass based on 100 parts by mass of the total of the metal complex represented by the formula (2) and the compound (B).

The antioxidant may be used alone or in combination of two or more.

Film >

The film of the present embodiment contains the composition for a light-emitting element. The film of the present embodiment is suitable as a light-emitting layer in a light-emitting element. The film of the present embodiment can be produced by a wet method using ink, for example. The film according to the present embodiment can be produced by a dry method such as a vacuum deposition method. Examples of the method for producing the film of the present embodiment by the dry method include a method of vapor deposition of the composition for a light-emitting element; and a method of co-evaporating the metal complex represented by the formula (2) and the compound (B).

The thickness of the film is usually 1nm to 10. Mu.m.

< light-emitting element >)

The light-emitting element of the present embodiment contains the above-described composition for a light-emitting element.

The light-emitting element of the present embodiment may include, for example, an anode, a cathode, and an organic layer containing the composition for a light-emitting element provided between the anode and the cathode.

[ layer Structure ]

The layer containing the composition for a light-emitting element of the present embodiment is usually at least 1 kind selected from the group consisting of a light-emitting layer, a hole-transporting layer, a hole-injecting layer, an electron-transporting layer, and an electron-injecting layer, and preferably a light-emitting layer. Each of these layers contains a light-emitting material, a hole-transporting material, a hole-injecting material, an electron-transporting material, and an electron-injecting material. Each of these layers may be formed using a light-emitting material, a hole-transporting material, a hole-injecting material, an electron-transporting material, or an electron-injecting material by the same method as that for manufacturing the film described above.

The light-emitting element has a light-emitting layer between an anode and a cathode. The light-emitting element of the present embodiment preferably has at least 1 layer of the hole injection layer and the hole transport layer between the anode and the light-emitting layer from the viewpoint of hole injection property and hole transport property, and preferably has at least 1 layer of the electron injection layer and the electron transport layer between the cathode and the light-emitting layer from the viewpoint of electron injection property and electron transport property.

Examples of the material of the hole transporting layer, the electron transporting layer, the light emitting layer, the hole injecting layer, and the electron injecting layer include the hole transporting material, the electron transporting material, the light emitting material, the hole injecting material, and the electron injecting material, respectively, in addition to the composition for a light emitting element according to the present embodiment.

In the production of the light-emitting element, in the case where the material of the hole-transporting layer, the material of the electron-transporting layer, and the material of the light-emitting layer are soluble in a solvent used in the formation of layers adjacent to the hole-transporting layer, the electron-transporting layer, and the light-emitting layer, respectively, the material preferably has a crosslinking group so as to avoid dissolution of the material in the solvent. After each layer is formed using a material having a crosslinking group, the crosslinking group is crosslinked, whereby the layer can be insolubilized.

In the light-emitting element of the present embodiment, as a method for forming each layer such as a light-emitting layer, a hole-transporting layer, an electron-transporting layer, a hole-injecting layer, and an electron-injecting layer, in the case of using a low-molecular compound, for example, a dry method such as a vacuum deposition method using powder, a wet method such as a method for forming a film by using a solution or a molten state, and in the case of using a high-molecular compound, for example, a wet method such as a method for forming a film by using a solution or a molten state can be mentioned. The order, number, and thickness of the stacked layers are adjusted in consideration of, for example, light emission efficiency, driving voltage, and luminance lifetime.

[ substrate/electrode ]

The substrate in the light-emitting element may be any substrate that can form an electrode and does not undergo chemical change when the organic layer is formed, and may be, for example, a substrate formed of a material such as glass, plastic, or silicon. In the case of an opaque substrate, it is preferable that the electrode furthest from the substrate is transparent or translucent.

Examples of the material of the anode include conductive metal oxides and semitransparent metals, and indium oxide, zinc oxide and tin oxide are preferable; conductive compounds such as Indium Tin Oxide (ITO) and indium zinc oxide; silver and palladium and copper complexes (APC); NESA, gold, platinum, silver, copper.

Examples of the material of the cathode include metals such as lithium, sodium, potassium, rubidium, cesium, beryllium, magnesium, calcium, strontium, barium, aluminum, zinc, and indium; more than 2 kinds of alloys among them; an alloy of 1 or more of them with 1 or more of silver, copper, manganese, titanium, cobalt, nickel, tungsten, tin; and graphite intercalation compounds. Examples of the alloy include magnesium-silver alloy, magnesium-indium alloy, magnesium-aluminum alloy, indium-silver alloy, lithium-aluminum alloy, lithium-magnesium alloy, lithium-indium alloy, and calcium-aluminum alloy.

The anode and the cathode may each have a laminated structure of 2 or more layers.

[ use ]

The light-emitting element of the present embodiment can be suitably used as a light source for backlight of a liquid crystal display device, a light source for illumination, organic EL illumination, a display device (for example, an organic EL display and an organic EL television) of a computer, a television, a portable terminal, or the like.

Although the preferred embodiments of the present invention have been described above, the present invention is not limited to these.

Examples

The present invention will be further described in detail with reference to examples, but the present invention is not limited to these examples.

In the examples, the polystyrene-equivalent number average molecular weight (Mn) and the polystyrene-equivalent weight average molecular weight (Mw) of the polymer compound were determined by Size Exclusion Chromatography (SEC) using tetrahydrofuran as the mobile phase.

The polymer compound to be measured was dissolved in tetrahydrofuran at a concentration of about 0.05 mass%, and 10. Mu.L was injected into SEC. The mobile phase was circulated at a flow rate of 1.0 mL/min. As a column, PLgel MIXED-B (manufactured by Polymer Laboratories) was used. The detector used was a UV-VIS detector (manufactured by Tosoh, trade name: UV-8320 GPC).

In the examples, ΔE for the compounds _ST For calculation of the values of (2), the ground state of the compound was structurally optimized by using the density functional method of B3LYP level, and this was used asThe basis function is 6-31G. Then, using Gaussian09 as a quantum chemical calculation program, ΔE of the compound was calculated by a time-dependent density functional method of B3LYP level _ST 。

In the examples, the maximum peak wavelength of the luminescence spectrum of the metal complex was measured at room temperature by a spectrophotometer (manufactured by Japanese Spectroscopy Co., ltd., FP-6500). The metal complex is dissolved in xylene at about 0.8X10 ^-4 A xylene solution having a concentration of mass% dissolved therein was used as a sample. As excitation light, UV light with a wavelength of 325nm was used.

Synthesis example M > Synthesis of Compounds M1 to M7

Compound M1 was synthesized according to the method described in International publication No. 2015/145871.

Compound M2 was synthesized according to the method described in International publication No. 2013/146806.

Compound M3 was synthesized according to the method described in International publication No. 2005/049546.

Compound M4 was synthesized according to the method described in japanese patent application laid-open No. 2010-189630.

Compound M5 and compound M7 were synthesized according to the method described in International publication No. 2002/045184.

Compound M6 was synthesized according to the method described in international publication No. 2011/049241.

[ chemical formula 20]

Synthesis example HTL-1 > Synthesis of Polymer HTL-1

The polymer compound HTL-1 was synthesized using the compounds M1, M2 and M3 according to the method described in International publication No. 2015/145871. The Mn of the high molecular compound HTL-1 is 2.3X10 ⁴ Mw is 1.2X10 ⁵ 。

The polymer compound HTL-1 was calculated as 45:5:50, a copolymer having a structural unit derived from the compound M1, a structural unit derived from the compound M2 and a structural unit derived from the compound M3.

Synthesis example HTL-C1 > Synthesis of Polymer HTL-C1

The polymer compound HTL-C1 was synthesized using the compound M4 and the compound M3 according to the method described in International publication No. 2015/194448. The Mn of the high molecular compound HTL-C1 is 4.5X10 ⁴ Mw is 1.5X10 ⁵ 。

The polymer compound HTL-C1 was 50:50, and a structural unit derived from a compound M4 and a structural unit derived from a compound M3.

Synthesis example HTL-2 > Synthesis of Polymer HTL-2

The polymer compound HTL-2 was synthesized using the compounds M7, M5 and M6 according to the method described in International publication No. 2011/049241. The Mn of the high molecular compound HTL-2 is 8.9X10 ⁴ Mw is 4.2X10 ⁵ 。

The polymer compound HTL-2 was calculated as 50:42.5:7.5 a copolymer having a structural unit derived from the compound M7, a structural unit derived from the compound M5 and a structural unit derived from the compound M6.

Synthesis and acquisition of Metal complexes G1-G4, firpic and Metal complexes R1-R7

As the metal complex G1, the metal complex R2, the metal complex R3, and the metal complex R4, those manufactured by Luminescence Technology corporation were used.

The metal complex G2 was synthesized according to the method described in Japanese patent application laid-open No. 2013-237789.

The metal complex G3 was synthesized according to the method described in international publication No. 2009/131255.

The metal complex G4 was synthesized according to the method described in japanese patent application laid-open No. 2014-224101 and international publication No. 2009/131255.

Firpic used was manufactured by Aldrich.

The metal complex R1 was manufactured by American Dye Source.

The metal complex R5 was synthesized according to the method described in JP 2006-188673A.

The metal complex R6 was synthesized according to the method described in Japanese patent application laid-open No. 2011-105701.

The metal complex R7 was synthesized according to the method described in JP-A2008-179617.

[ chemical formula 21]

[ chemical formula 22]

[ chemical formula 23]

The maximum peak wavelength of the luminescence spectrum of the metal complex G1 was 510nm.

Metal complex G ² The maximum peak wavelength of the luminescence spectrum of (2) was 508nm.

The maximum peak wavelength of the luminescence spectrum of the metal complex G3 was 514nm.

The maximum peak wavelength of the emission spectrum of the metal complex G4 was 544nm.

The maximum peak wavelength of the emission spectrum of Firpic is 470nm.

The maximum peak wavelength of the luminescence spectrum of the metal complex R1 is 618nm.

The maximum peak wavelength of the luminescence spectrum of the metal complex R2 was 579nm.

The maximum peak wavelength of the luminescence spectrum of the metal complex R3 is 620nm.

The maximum peak wavelength of the luminescence spectrum of the metal complex R4 was 580nm.

The maximum peak wavelength of the luminescence spectrum of the metal complex R5 was 619nm.

The maximum peak wavelength of the luminescence spectrum of the metal complex R6 was 611nm.

The maximum peak wavelength of the luminescence spectrum of the metal complex R7 was 594nm.

< acquisition and Synthesis of Compounds H1, T1 and B1-B3 >)

As the compound H1 and the compound B1, those manufactured by Luminescence Technology corporation were used.

Compound T1 was synthesized according to the method described in International publication No. 2018/062278.

Compound B2 and compound B3 were synthesized according to the method described in International publication No. 2015/102118.

[ chemical formula 24]

[ chemical formula 25]

ΔE of Compound T1 _ST 0.109eV.

ΔE of Compound B1 _ST Is 0.494eV.

ΔE of Compound B2 _ST 0.471eV.

ΔE of Compound B3 _ST 0.479eV.

Example D1 > production and evaluation of light-emitting element D1

(formation of anode and hole injection layer)

An ITO film was formed on a glass substrate by sputtering to a thickness of 45nm, thereby forming an anode. ND-3202 (manufactured by Nissan chemical industry) as a hole injection material was formed on the anode by spin coating at a thickness of 35 nm. The substrate on which the hole injection layer was laminated was heated at 50 ℃ for 3 minutes and 230 ℃ for 15 minutes on a hot plate under an atmospheric atmosphere, thereby forming a hole injection layer.

(formation of hole transporting layer)

The high molecular compound HTL-1 was dissolved in xylene at a concentration of 0.7 mass%. Using the obtained xylene solution, a film was formed on the hole injection layer by spin coating at a thickness of 20nm, and heated on a heating plate at 180 ℃ under nitrogen atmosphere for 60 minutes, thereby forming a hole transport layer.

(formation of light-emitting layer)

Compound H1, compound B1, and metal complex G3 (compound H1/compound B1/metal complex g3=66% by mass/4% by mass/30% by mass) were dissolved in toluene at a concentration of 2% by mass. The resulting toluene solution was used to form a film on the hole transport layer by spin coating at a thickness of 60nm, and heated at 130℃for 10 minutes under a nitrogen atmosphere, thereby forming a light-emitting layer.

(formation of cathode)

The substrate on which the light-emitting layer was formed was depressurized to 1.0X10 in a vapor deposition machine ^-4 After Pa or less, sodium fluoride was deposited as a cathode on the light-emitting layer at about 4nm, and then aluminum was deposited on the sodium fluoride layer at about 80nm. After vapor deposition, the substrate on which the cathode was formed was sealed with a glass substrate, thereby producing a light-emitting element D1.

(evaluation of light-emitting element)

By applying a voltage to the light-emitting element D1, EL emission was observed. Measurement of 100cd/m ² Luminous efficiency at time [ lm/W]And CIE chromaticity coordinates.

Examples D2 to D3 and comparative examples CD1 to CD2 > production and evaluation of light-emitting elements D2, D3, CD1 and CD2

Light-emitting elements D2, D3, CD1 and CD2 were produced in the same manner as in example D1, except that the materials described in table 1 were used instead of "compound H1, compound B1 and metal complex G3 (compound H1/compound B1/metal complex g3=66% by mass/4% by mass/30% by mass)" in example D1 (formation of a light-emitting layer).

EL emission is observed by applying voltages to the light emitting elements D2, D3, CD1, and CD 2. Measurement of 100cd/m ² Luminous efficiency at time [ lm/W]And CIE chromaticity coordinates.

The results of examples D1 to D3 and comparative examples CD1 to CD2 are shown in Table 1. The relative values of the light-emitting efficiencies of the light-emitting elements D1 to D3 and CD2 when the light-emitting efficiency of the light-emitting element CD1 was set to 1.0 are shown.

TABLE 1

/>

Examples D4 to D6 and comparative example CD3 > production and evaluation of light-emitting elements D4 to D6 and CD3

Light-emitting elements D4 to D6 and CD3 were produced in the same manner as in example D1, except that the materials described in table 2 were used instead of "compound H1, compound B1 and metal complex G3 (compound H1/compound B1/metal complex g3=66 mass%/4 mass%/30 mass%)" in example D1 (formation of a light-emitting layer).

EL emission was observed by applying voltages to the light emitting elements D4 to D6 and CD3. Measurement of 2000cd/m ² Luminous efficiency at time [ lm/W]And CIE chromaticity coordinates.

The results of examples D4 to D6 and comparative example CD3 are shown in Table 2. The relative values of the light-emitting efficiencies of the light-emitting elements D4 to D6 when the light-emitting efficiency of the light-emitting element CD3 was set to 1.0 are shown.

TABLE 2

Examples D7 to D8 and comparative example CD4 > production and evaluation of light-emitting elements D7, D8 and CD4

Light-emitting elements D7, D8, and CD4 were produced in the same manner as in example D1 except that the materials described in table 3 were used instead of "compound H1, compound B1, and metal complex G3 (compound H1/compound B1/metal complex g3=66 mass%/4 mass%/30 mass%)" in example D1 (formation of a light-emitting layer), and "polymer compound HTL-C1" was used instead of "polymer compound HTL-1" in example D1 (formation of a hole-transporting layer).

EL emission was observed by applying voltages to the light-emitting elements D7, D8, and CD4. Measurement of 10000cd/m ² Luminous efficiency at time [ lm/W]And CIE chromaticity coordinates.

The results of examples D7 to D8 and comparative example CD4 are shown in Table 3. The relative values of the light-emitting efficiencies of the light-emitting elements D7 and D8 when the light-emitting efficiency of the light-emitting element CD4 was set to 1.0 are shown.

TABLE 3

Example D9 > production and evaluation of light-emitting element D9

(formation of anode and hole injection layer)

An ITO film was formed on a glass substrate by sputtering to a thickness of 45nm, thereby forming an anode. ND-3202 (manufactured by Nissan chemical industry) as a hole injection material was formed on the anode by spin coating at a thickness of 50 nm. The substrate on which the hole injection layer was laminated was heated at 50 ℃ for 3 minutes and 230 ℃ for 15 minutes on a hot plate under an atmospheric atmosphere, thereby forming a hole injection layer.

(formation of hole transporting layer)

The high molecular compound HTL-2 was dissolved in xylene at a concentration of 0.7 mass%. Using the obtained xylene solution, a film was formed on the hole injection layer by spin coating at a thickness of 20nm, and heated on a heating plate at 180 ℃ under nitrogen atmosphere for 60 minutes, thereby forming a hole transport layer.

(formation of light-emitting layer)

Compound H1, compound B1, and metal complex R7 (compound H1/compound B1/metal complex r7=81% by mass/4% by mass/15% by mass) were dissolved in toluene at a concentration of 2% by mass. The resulting toluene solution was used to form a film on the hole transport layer by spin coating at a thickness of 60nm, and heated at 130℃for 10 minutes under a nitrogen atmosphere, thereby forming a light-emitting layer.

(formation of cathode)

The substrate with the light-emitting layer formed thereon was depressurized to 1.0X10- ⁴ After Pa or less, sodium fluoride was deposited as a cathode on the light-emitting layer at about 4nm, and then aluminum was deposited on the sodium fluoride layer at about 80nm. After vapor deposition, the substrate on which the cathode was formed was sealed with a glass substrate, thereby producing a light-emitting element D9.

(evaluation of light-emitting element)

By applying a voltage to the light-emitting element D9, EL emission was observed. Measurement of 1000cd/m ² Luminous efficiency at time [ lm/W]And CIE chromaticity coordinates.

Examples D10 to D11 and comparative example CD5 > production and evaluation of light-emitting elements D10, D11 and CD5

Light-emitting elements D10, D11, and CD5 were produced in the same manner as in example D9, except that the materials described in table 4 were used instead of "compound H1, compound B1, and metal complex R7 (compound H1/compound B1/metal complex r7=81%/4%/15%)" in example D9 (formation of a light-emitting layer).

EL emission is observed by applying voltages to the light emitting elements D10, D11, and CD5. Measurement of 1000cd/m ² Luminous efficiency at time [ lm/W]And CIE chromaticity coordinates.

The results of examples D9 to D11 and comparative example CD5 are shown in Table 4. The relative values of the light-emitting efficiencies of the light-emitting elements D9 to D11 are shown when the light-emitting efficiency of the light-emitting element CD5 is set to 1.0.

TABLE 4

Examples D12 to D13 and comparative example CD6 > production and evaluation of light-emitting elements D12, D13 and CD6

Light-emitting elements D12, D13, and CD6 were produced in the same manner as in example D9, except that the materials described in table 5 were used instead of "compound H1, compound B1, and metal complex R7 (compound H1/compound B1/metal complex r7=81%/4%/15%)" in example D9 (formation of a light-emitting layer).

EL emission was observed by applying voltages to the light-emitting elements D12, D13, and CD 6. Measurement 2500cd/m ² Luminous efficiency at time [ lm/W]And CIE chromaticity coordinates.

The results of examples D12 to D13 and comparative example CD6 are shown in Table 5. The relative values of the light-emitting efficiencies of the light-emitting elements D12 and D13 when the light-emitting efficiency of the light-emitting element CD6 was set to 1.0 are shown.

TABLE 5

Industrial applicability

The composition of the present invention is useful for the production of a light-emitting element having excellent light-emitting efficiency.

Claims

1. A light-emitting element comprising an anode, a cathode, and an organic layer comprising a composition for a light-emitting element, which is provided between the anode and the cathode,

the composition for a light-emitting element comprises:

a metal complex represented by the formula (2);

having boron atoms contained within the ring and selected from oxygen atoms, sulfur atoms, selenium atoms, sp ³ A compound B of a condensed heterocyclic skeleton B of at least 1 of a carbon atom and a nitrogen atom, which is a low-molecular compound; and

a compound represented by the formula (H-1),

in the method, in the process of the invention,

M ² represents rhodium atoms, palladium atoms, iridium atoms or platinum atoms,

n ³ represents an integer of 1 or more, n ⁴ Represents an integer of 0 or more, wherein M is ² Is rhodium or iridium atomIn the case of son, n ³ +n ⁴ 3, at M ² In the case of palladium or platinum atoms, n ³ +n ⁴ Is the number of the water-soluble polymer in the water solution to be 2,

E ^L represents a carbon or nitrogen atom, E ^L Where there are a plurality, each of which is optionally the same or different,

ring L ¹ Represents an aromatic heterocyclic ring comprising a six-membered ring, which ring optionally has substituents which, in the case where there are a plurality of substituents, are optionally identical or different and are optionally bonded to one another to form a ring together with the atoms to which each is bonded, ring L ¹ Where there are a plurality, they are optionally the same or different,

ring L ² Represents an aromatic hydrocarbon ring or an aromatic heterocyclic ring, which rings optionally have substituents which, in the case where a plurality are present, are optionally identical or different and are optionally bonded to one another to form a ring together with the atoms to which each is bonded, a ring L ² Where there are a plurality, they are optionally the same or different,

ring L ¹ Optionally having substituents and ring L ² Optionally having substituents which are optionally identical or different and which are optionally bonded to one another to form, together with the atoms to which they are each bonded, a ring,

wherein, the ring L ¹ And ring L ² Of which at least 1 has as a substituent a group represented by the formula (1-T), and in the case where there are plural groups represented by the formula (1-T), they are optionally the same or different,

A ³ －G ² －A ⁴ Bidentate ligand, A, representing anionicity ³ And A ⁴ Each independently represents a carbon atom, an oxygen atom or a nitrogen atom, which are optionally atoms constituting a ring, G ² Represents a single bond, or is bonded with A ³ And A ⁴ Radicals A which together form a bidentate ligand ³ －G ² －A ⁴ Where there are a plurality, they are optionally the same or different,

-R ^1T (1-T)

wherein R is ^1T Represents alkyl, cycloalkyl, alkoxy, cycloalkoxy, arylAn oxy group, an aryl group, a monovalent heterocyclic group or a substituted amino group, these groups optionally having a substituent, which in the case where there are a plurality of substituents, are optionally the same or different, are optionally bonded to each other to form a ring together with the atom to which each is bonded,

in the method, in the process of the invention,

Ar ^H1 and Ar is a group ^H2 Each independently represents an aryl group, a monovalent heterocyclic group or a substituted amino group, which groups optionally have substituents which, in the case where there are a plurality of substituents, are optionally identical or different and are optionally bonded to each other to form a ring together with the atom to which each is bonded,

n ^H1 represents an integer of 0 or more,

L ^H1 represents arylene, divalent heterocyclic, alkylene or cycloalkylene radicals, which optionally have substituents which, if there are a plurality of them, are optionally identical or different and are optionally bonded to one another to form a ring together with the atoms to which they are each bonded, L ^H1 Where there are a plurality, they are optionally the same or different.

2. The light-emitting device according to claim 1, wherein,

the ring L ¹ Is a pyridine ring, a diazabenzene ring, an azanaphthalene ring or a naphthyridine ring, these rings optionally having substituents.

3. The light-emitting device according to claim 2, wherein,

the ring L ¹ Is a pyridine ring, a diazabenzene ring, a quinoline ring or a naphthyridine ring, which rings may have a substituent, and

the R is ^1T Is alkyl, cycloalkyl, aryl, monovalent heterocyclic or substituted amino, which groups optionally have substituents.

4. The light-emitting device according to claim 2, wherein,

the ring L ¹ Is an isoquinoline ring optionally having a substituent, and

the R is ^1T Is aryl, monovalent heterocyclic or substituted amino, which groups optionally have substituents.

5. The light-emitting element according to any one of claim 1 to 4, wherein,

the ring L ² Is a benzene ring, a pyridine ring or a diazabenzene ring, and these rings may optionally have a substituent.

6. The light-emitting element according to any one of claim 1 to 4, wherein,

the R is ^1T Is aryl optionally substituted or monovalent heterocyclic optionally substituted.

7. The light-emitting element according to any one of claim 1 to 4, wherein,

The condensed heterocyclic skeleton b contains a boron atom and at least 1 selected from the group consisting of an oxygen atom, a sulfur atom and a nitrogen atom within the ring.

8. The light-emitting device according to claim 7, wherein,

the fused heterocyclic skeleton b contains boron atoms and nitrogen atoms within the ring.

9. The light-emitting element according to any one of claim 1 to 4, wherein,

the compound B is a compound shown in a formula (1-1), a compound shown in a formula (1-2) or a compound shown in a formula (1-3),

in the method, in the process of the invention,

Ar ¹ 、Ar ² and Ar is a group ³ Each independently representsAn aromatic hydrocarbon group or a heterocyclic group, which groups optionally have a substituent, which substituents, in the case where a plurality are present, are optionally the same or different, are optionally bonded to each other to form a ring together with the atoms to which each is bonded,

Y ¹ represents an oxygen atom, a sulfur atom, a selenium atom, -N (Ry) -represented group, an alkylene group or a cycloalkylene group, these groups optionally having a substituent, which in the case where there are a plurality of substituents, are optionally the same or different, are optionally bonded to each other to form a ring together with the atoms to which each is bonded,

Y ² and Y ³ Each independently represents a single bond, an oxygen atom, a sulfur atom, a selenium atom, -N (Ry) -represented group, alkylene or cycloalkylene group, which groups optionally have a substituent, which groups are optionally the same or different in the presence of a plurality, and are optionally bonded to each other to form a ring together with the atom to which each is bonded, ry represents a hydrogen atom, alkyl, cycloalkyl, aryl or monovalent heterocyclic group, which groups optionally have a substituent, which groups are optionally the same or different in the presence of a plurality, are optionally bonded to each other to form a ring together with the atom to which each is bonded, ry is optionally the same or different in the presence of a plurality, ry is optionally bonded to Ar directly or via a linking group ¹ 、Ar ² Or Ar ³ And (5) bonding.

10. The light-emitting device according to claim 9, wherein,

the Y is ¹ Said Y ² And said Y ³ Is an oxygen atom, a sulfur atom or a group represented by-N (Ry) -.

11. The light-emitting device according to claim 10, wherein,

the Y is ¹ Said Y ² And said Y ³ is-N (Ry) -the group shown.

12. The light-emitting element according to any one of claims 1 to 4, 8, 10, 11, wherein,

the absolute value of the difference between the energy level of the lowest triplet excited state of the compound B and the energy level of the lowest singlet excited state of the compound B is 0.50eV or less.

13. The light-emitting element according to any one of claims 1 to 4, 8, 10, 11, wherein,

14. A composition for a light-emitting element, comprising:

a metal complex represented by the formula (2);

A compound represented by the formula (H-1),

in the method, in the process of the invention,

n ³ represents an integer of 1 or more, n ⁴ Represents an integer of 0 or more, wherein M is ² In the case of rhodium or iridium atoms, n ³ +n ⁴ 3, at M ² In the case of palladium or platinum atoms, n ³ +n ⁴ Is the number of the water-soluble polymer in the water solution to be 2,

ring L ¹ Represents an aromatic heterocyclic ring comprising a six-membered ring, the ring optionally having substituents which, in the case where there are a plurality of substituents, are optionally the same or different,optionally bonded to each other to form a ring together with the atoms to which each is bonded, ring L ¹ Where there are a plurality, they are optionally the same or different,

-R ^1T (1-T)

wherein R is ^1T Represents alkyl, cycloalkyl, alkoxy, cycloalkoxy, aryloxy, aryl, monovalent heterocyclic radicals or substituted amino radicals, which optionally have substituents which, if present in a plurality, are optionally identical or different and are optionally bonded to one another to form, together with the atoms to which they are each bonded, a ring,

in the method, in the process of the invention,

n ^H1 represents an integer of 0 or more,

15. The composition for a light-emitting element according to claim 14, wherein,

16. The composition for a light-emitting element according to claim 14, wherein,

the ring L ¹ Is an isoquinoline ring optionally having a substituent, and R is ^1T Is aryl, monovalent heterocyclic or substituted amino, which groups optionally have substituents.

17. The composition for a light-emitting element according to any one of claim 14 to 16, wherein,

18. The composition for a light-emitting element according to any one of claim 14 to 16, wherein,